Titel: Large terminal mosaic 3p26 deletion (8.5Mb) in a healthy man and subsequent prenatal diagnosis
ID: P-CytoG-130
Art: Postertalk
Redezeit: 2 min
Session: Poster Session
BasEpi / CancG / CytoG

Referent: Eva Daumiller (Stuttgart/DE)

Abstract - Text


Chromosome analysis was performed for recurrent miscarriages in an otherwise healthy couple. In the male partner, mosaicism with terminal deletion in chromosome 3, from 3p26 to p-terminal, was detected. His karyotype in lymphocytes was mos 46,XY,del(3)(:p26->qter)[21]/46,XY[5]. Subsequent FISH analysis with DNA probes for the terminal regions of the short arms of chromosome 3 confirmed these findings. Microarray analysis determined the size of the 3p26 deletion as of 8.5Mb. The deletion encompassed several genes including ITPR1.

Non-mosaic terminal 3p26 deletions of similar size have been described in patients with developmental delay and dysmorphic features. The abnormal karyotype might explain the recurrent miscarriages of this couple. However, this could not be proven, since fetal tissue from previous miscarriages was not available.

Deletions and mutations in the gene ITPR1 are associated with Gillespie syndrome, an inherited disorder that involves eye abnormalities, weak muscle tone from birth (congenital hypotonia), problems with balance and coordinating movements (ataxia), and mild to moderate intellectual disability. The 35-year-old male described here does not have any of these features.

Based on the chromosome finding and the increased risk of a child with 3p- syndrome, the couple decided for prenatal diagnosis with chorionic villus sampling in their next pregnancy. Fortunately, two normal chromosomes 3 were found and a healthy baby was born.